Class: Racc::LocationPointer

Inherits:
Object
  • Object
show all
Defined in:
lib/racc/grammar.rb

Overview

A set of rule and position in it’s RHS. Note that the number of pointers is more than rule’s RHS array, because pointer points right edge of the final symbol when reducing.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(rule, i, sym) ⇒ LocationPointer

Returns a new instance of LocationPointer.



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# File 'lib/racc/grammar.rb', line 811

def initialize(rule, i, sym)
  @rule   = rule
  @index  = i
  @symbol = sym
  @ident  = @rule.hash + i
  @reduce = sym.nil?
end

Instance Attribute Details

#ident ⇒ Object (readonly) Also known as: hash

Returns the value of attribute ident.



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# File 'lib/racc/grammar.rb', line 825

def ident
  @ident
end

#index ⇒ Object (readonly)

Returns the value of attribute index.



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# File 'lib/racc/grammar.rb', line 820

def index
  @index
end

#reduce ⇒ Object (readonly) Also known as: reduce?

Returns the value of attribute reduce.



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# File 'lib/racc/grammar.rb', line 827

def reduce
  @reduce
end

#rule ⇒ Object (readonly)

Returns the value of attribute rule.



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# File 'lib/racc/grammar.rb', line 819

def rule
  @rule
end

#symbol ⇒ Object (readonly) Also known as: dereference

Returns the value of attribute symbol.



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# File 'lib/racc/grammar.rb', line 821

def symbol
  @symbol
end

Instance Method Details

#before(len) ⇒ Object 



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# File 'lib/racc/grammar.rb', line 853

def before(len)
  @rule.ptrs[@index - len] or ptr_bug!
end

#eql?(ot) ⇒ Boolean Also known as: ==

Returns:

  • (Boolean) 


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# File 'lib/racc/grammar.rb', line 837

def eql?(ot)
  @hash == ot.hash
end

#head? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/racc/grammar.rb', line 843

def head?
  @index == 0
end

#next ⇒ Object Also known as: increment 



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# File 'lib/racc/grammar.rb', line 847

def next
  @rule.ptrs[@index + 1] or ptr_bug!
end

#to_s ⇒ Object Also known as: inspect 



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# File 'lib/racc/grammar.rb', line 830

def to_s
  sprintf('(%d,%d %s)',
          @rule.ident, @index, (reduce?() ? '#' : @symbol.to_s))
end